Screw pump



F. A. FAY.

SCREW PUMP.

APPLICATION FILED APR. I3, 1920.

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LABQSQQL @y M'ml mwen/Er Patented @cto 3l, i922..

entre FRANK A. FAY, OF CALDWELL, NEW JERSEY, .ASSIGNOR T0 WILLIEAM E.QUIMBY, INC., 0F NEWARK, NEW FERSEY, .A CORPORATION-0F NEW YRK.

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lapplication lecl April-13,

To all whom t may concern:

Be it known that l, F RANK A. FAY, a citizen of the United States,residingat Caldwell, in the county of Essex and State of New Jersey,have invented certain new and useful improvements in Screw Pumps, ofwhich the following is a specification.

This invention relates to a screwpump of the type illustrated in LettersPatent No.- 529,837,V -issued on November 27, 1894, to William E.Quimby, in which two pairs of intermeshing screws, right and leftandleft and right, respectively, are mounted in the same horizontalplane on .parallel shafts journaled in bearings in the-heads of a shellbored to fit the perimeters of the unintermeshed portions of the screws.rlhe screws have threads of two or more convolutions and projectinghollow cores which, by holding the outer ends of the threads spacedapart from the heads of the casing and their inner ends spaced apartfrom each other, provide two endchambers and one centrally locatedchamber, and the necessary inlet and outlet openings to these chambersare formed through the lower and upper walls of the casing.

j lt has been found in practice that suchv a pump, while exceedinglyecient with low pressures, could not 'be used commercially Awithpressures exceeding-about two hundred pounds per square inch, since thewearing away not only of the vscrews but of the inner walls of theshell,'due -to the unbalanced vportions of the screws adjoining, and thevertical thruston the screw shafts within, the central chamber soonproduced a slip of the fluid which destroyed the eciency of the pump. yp t Bymy present invention, which conslsts briefly in providingadditional bearings for the two shafts within the chamber at the centerof the shell, l have obviated this diiiiculty and have produced a pumpwhich can be operated efficiently at pressures of ve hundred pounds andupwards and hence has a new and much widerl eld of utility, beingadapted, for example, for use as a high pressure pump for pumping heavyfuel oils.

rlhe invention is illustrated in the accompanying drawings, in which-Figure l isa plan view, partly 1n horizontal section, 4of a Quimby screwpump embodying my improvements; Fig. 2, a side 1920. Serial No.373,623.'

elevation, partly in verticalJ section; and A Fig. 3, a transversevertical section atthe longitudinal center of the shell. j

As here shown, the shell l is mounted upon the usual bed-plate, and thetwo shafts 2 and 3, carrying the screws 4: 5 and 6 7 and extendigigthrough stuiing boxes in the heads of the shell, are journaled inbearings in standards carried by the bed-plate and are geared togetherand driven by a pulley fixed to the end of one of the shafts, all inthefusual or in any suitable manner.

For the new intermediate bearings for the screw shafts, a standard isprovided` by a partial transverse wall 8, which divides the lower partonly of the slightly elongated central chamber 9 and has formed thereinintersecting cylindrical openings lOand ll corresponding to the bore ofthe shell and in alignmenttherewith, and two Collars l2 and 13,flattened along one side, which, serving as journal boxes, are rotatablysecured upon the respective shafts between the opposed ends of thehollow cores of the screws and, when the parts of the pump areassembled, fit into and are held against rotation within the openings inthe standard. rlhe two collars may, of course, be integral, if desired.

By the central bearing support thus provided for the screw shafts, theunbalanced portions ofthe exposed screw threads are counter-balanced andthe wearito which the parts have heretofore been subjected b thevertical thrust thereon 1s substantially e iminated, and what has beenfor all practical purposes a low pressure pump is converted 90 into anefficient and durable high pressure J pump.

What I claim as new, and desire to secure by Letters Patent, isj l. Ascrew pump of the type described comprising a suitable casing, twoparallel shafts journaled 'in bearings in the heads of the casing andmounted thereontwo pairs of intermeshing right and left screws withthreads having a plurality of convolutions and held spaced apart attheir inner ends to form within the shell a short centrally locatedchamber open throughout to the ends of the screws, and a supplementarybearing for the screw shafts intermediate the opposed inner ends of thescrews.

2. ln a screw pump of the type described, the combination, with asuitable shell andf .l parts of the pump 10 vtwo pairs of intermeshingright and left screws mounted upon parallel shafts mounted in the headsofthe shell and spaced apart -at their inner ends to form Within theshell a short central chamber open throughout the ends yof the screws,of means providing a bearing for the shafts withinthe central chamberwhichv permit the assembling of the with the screws in place upon theshafts.

3. In a screw pump of the character described, the combination with asuitable shell and two rpairs of intermeshing right and left screws,with threadshaving a pluralityA of convolutions -and hollow coresprojecting from the`ends thereof, mounted-uponl .FRANK A. BAY.

